Stay bolt for boilers



Oct. 19, 1926 1, 03,579

L. BUDWELL STAY BOLT FOR BOILERS Filed Jan. 1926 I414 23 I /9 8 j M M be vPatented Oct. 19, 192 6.

- UNITED STATES LEIGH BUDWQELL, OI RICHMOND, VIRGINIA.

STAY BOLT FOB BOILERS.

Application filed January as, 1926. Serial No. 83,359.

This invention relates to flexible staybolts for steam boilers and more particularly to a tell tale staybolt especially adapted for use in connection with locomotive boilers.

An important object of the invention is to provide a staybolt structure which will automatically give warning when the staybolt becomes cracked or otherwise damaged within the steam and water space.

A still further object is to provide a staybolt of the character mentioned provided with a steam passage which is adapted to communicate with the interior of the steam and water space if the bolt becomes cracked or otherwise damaged, the steam passage communicating with the atmosphere to vent the steam therefrom to give a visible warning.

A still further object is to provide a staybolt provided with an opening extending throughout its length and to cover the outer end of the sta bolt with a cap having a vent therein w ereby steam will escape to the atmosphere to give visible warning if the staybolt becomes cracked, thus permitting the escape of steam from the steam and water space into the opening extending through the staybolt.

A still further object is to provide a staybolt having an axial drilled opening extending throughout its length and to provide a cap covering the outer end of the staybolt, the cap also being provided with an axial opening in direct alinement with the drilled opening of the staybolt to permit the escape of steam to the atmosphere to provide a visible signal if the staybolt becomes cracked or otherwise damaged, permitting steam to pass into the drilled opening in the staybolt, means being provided associated with the staybolt to prevent the escape of any steam which may pass between the ball of the staybolt and the sleeve within which it is seated.

A still further object is to provide a staybolt of the character just mentioned wherein the means for preventing escape of steam past the ball of the staybolt comprises a convolute diaphragm, one end of the diaphragm being secured against the outer end :of the sleeve within which the ball. of the staybolt seats, the other end of the diaphragm being secured against the staybolt.

A still further object is to provide packing means associated with the ends of the diaphragm referred to for the prevention of the escape of steam past the ends of the diaphragm.

In the drawings I have shown one embodlment of the invention. In this showing:

Figure 1 is a central longitudinal sectional view through a staybolt and associated boiler sheets,

Figure 2 is an enlarged sectional view of the diaphragm, and

Figure 3 is an enlarged central lon itudinal sectional view through the diap ragm and associated elements.

Referring to the drawings the numeral 10 designates the outer sheet of a locomotive boiler which is spaced from the usual fire sheet 11 to provide a steam and water space 12. A sleeve 13 is mounted in the outer sheet 10 in the usual manner and is provided with the usual socket 1 1, for a purpose to be described. A staybolt 15 extends through the sleeve 13 as will be apparent, and is threaded as at 16 at its inner end. When the device is assembled the inner extremity of the staybolt is riveted as at 17 against the fire side of the inner sheet 11. The staybolt 15 is provided with a ball 18 which seats within the socket 14, and the staybolt is provided with a longitudinal extension 19 whichprojects upwardly a substantial distance beyond the ball 18. This extended portion 19 is preferably hexagonal n cross section but it will be apparent that it may be formed of any polygonalshape. At its outer end, the extension 19 is provided with a shoulder for a purpose to be described, and the extremity 21 of the staybolt 1s externally threaded. As clearly shown in Figure 1, the staybolt is provided with an axial passage 22 extending throughout its length for a purpose to be described.

The sleeve is provided outwardly of the outer sheet 10 with an enlarged threaded portion 23 received within the internally threaded portion of a cap 24. The cap 24 may be provided with a hexagonal portion 25 to permit it to be turned into position, as will be understood. The upper end of the cap is substantially hemispherical in shape as shown at 26 and is provided at its outer end with a vent opening 27 arranged in axiai alinement with the passage 22.

Means are provided for preventing the escape of steam between the ball 18 and its seat 14. As shown in Figures 1 and 3, the numeral 28 designates a relatively heavy lit) convolute diaphragm. The diaphragm 81E- ployed may have any desired number of t e convolutions 29 as will be obvious. At its inner end the diaphragm extends outwardly as at 30, and the extremity is turned inwardly as at 31 and spaced from the adjacent portion 30 to receive asbestos or similar packing This construction provides an annular packing flange portion 33 which is adapted to be clamped against the outer end of the sleeve 13, as shown in Figure l, to provide a leak-proof joint. The opposite end of the diaphragm is provided with a cylindrical extension 34, as shown in detall in Figure 2, and this extension may be brazed or otherwise secured to a packing ring 35 preferably formed of bronze or similar.material. The ring 35 is adapted to seat against the shoulder 20 and is held tightly thereagainst by a nut 36.

The operation of the device is as follows:

In assembling the device, the threaded end 16 of the staybolt is inserted in its opening in the inner sheet 11 and tightened down to bring the ball 18 against its seat. The turning action of the staybolt may be accom-: plished by using a wrench on the hexagonal extension 19. After the bolt is in position, the inner end thereof is riveted as at 17. As is well known, the ball of a staybolt moves in axial alinement with the bolt to some slight extent. It is also well known that the inner end of the bolt swingsabout the center of the ball to some extent due to relative movement between the inner and outer boiler sheets. With the present invention, it will be apparent that the diaphragm 28 provides a flexible connection between the sleeve 13 and the extended portion of the staybolt to permit the swinging action of the inner end of the bolt. It also will be apparent that if the bolt moves axially to unseat the ball 18, the escape of steam passing between the ball and its seat will be prevented by means of the diaphragm 28. Obviously it is necessary to provide adiaphragm which is adapted to withstand the highest pressure to which the boiler is subjected. As previously stated the passage 22 extends throughout the length of the staybolt and this passage is alined with the vent 27 of the cap. If for any reason the staybolt becomes cracked or otherwise damaged within the steam and Water space, steam or water will escape into the passage 22 from whence it will pass outwardly through opposite ends thereof. The steam escaping through the outer end of the passage 22 will find its way to the atmosphere through the vent 27 of the cap, thus giving a visible warning to the effect that the staybolt has become damaged. Where the boiler is lagged with asbestos, the noise of the escaping steam is suflicient to give warning as to the damaged condition of the staybolt.

However, under any conditions, the steam condensing between the outer boiler sheet 10 and the lagging will drip out through the lagging, thuspresenting a visible signal. It will be apparent that the diaphragm em ployed is of substantial length whereby considerable flexibility is obtained to permit the relative movement of the parts, referred to.

It, is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoincd claims.

I claim:

1. A device of the character described comprising a staybolt extending throu h the inner and outer sheets of a boiler an provided throughout its length with a passage, a ball formed on said staybolt, a sleeve secured to the outer sheet of the boiler and provided with a socket for said ball, said staybolt being extended axially outwardly beyond said ball, and a diaphragm secured at one end to said sleeve, the opposite end of said diaphragm being secured to the axial extension of said staybolt.

2. A device of the character described comprising a staybolt extending throu h the inner and outer sheets of a boiler an provided throughout its length with a passage, a ball formed on said staybolt, a sleeve mounted in the outer sheet of the boiler and provided with a socket for said ball, said staybolt having an axial extension projecting outwardly beyond said ball a substantial distance, and a convolute diaphragm of substantial length secured at one end to said sleeve and at its opposite end to the outer end of said axial extension.

3. A device constructed in accordance with claim 2 wherein said diaphragm is provided at its inner end with an outstanding annular flange arranged against the outer end of said sleeve, and a cap arranged over said diaphragm and secured to said sleeve, said cap having a portion adapted to engage against the annular flange of said diaphragm and provided with an opening arranged in alinement with the passage in said staybolt.

4. A device constructed in accordance with claim 2 wherein said axial extension is provided with a reduced outer end forming a shoulder, a packing ring secured to the outer end of said diaphragm and arranged against said shoulder, and a nut threaded on the reduced end of said axial extension and engaging against said packing ring.

5. A device of the character described comprising a staybolt extending through the inner and outer sheets of a boiler and provided with a longitudinal passage extend ing throughout its length, a ball formed on said staybolt, a sleeve secured to the outer sheet of the boiler and provided with. a socket for said ball, said staybolt having an axial extension projecting outwardly a sub stantial distance beyond said ball, said extension having a reduced end forming a shoulder, a convolute diaphragm of substantial length surrounding said axial extension and provided intermediate its ends with a series of convolutions, the inner end of said diaphragm extending outwardly and having its extremity bent back upon itself, packing arranged within the adjacent portions of the outwardly extending portion of said diaphragm, the extremity of said diaphragm being arranged against the outer end of said sleeve, a ca arranged over said diaphragm and threaded on said sleeve, said cap having a shoulder adapted to engage against the outwardly extending portion of said diaphragm, a packing ring secured to the opposite end of said diaphragm and arranged against the shoulder of said axial extension, and a nut threaded on the reduced end of said axial extension and engaging against said packing ring, said reduced end extending at least as far outwardly as the outer end of said nut, said cap being provided with an opening arranged in axial alinement with the passage in said staybolt.

In testimony whereof I affix my signature.

LEIGH BUDWELL. 

